Lime-Colored History of War

Umakai Shintaro, a Russian diplomat originally from Japan, defects and goes to Sapporo to teach at a girls academy. However, that girls academy is not typical—it is on board the Amanohara, and the five girls Shintaro teaches are known as the Lime Unit—girls with the ability to summon powerful beings to fight for them. Shintaro eventually becomes their teacher and general in battle, and so the six embark on a weird and excessively erotic ...